Stephan’s Quintet NGC7317/18a/18b/19/20c

Stephan’s Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory. The group is the most studied of all the compact galaxy groups.

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Four of the five galaxies in Stephan’s Quintet form a physical association, a true galaxy group, Hickson Compact Group 92, and will likely merge with each other. Radio observations in the early 1970s revealed a mysterious filament of emission which lies in inter-galactic space between the galaxies in the group. This same region is also detected in the faint glow of ionized atoms seen in the visible part of the spectrum as a green arc.

This little group of Galaxies  was captured by me using my telescope at the Wilson Coulee Observatory.  In 2022, one of the first published images by the James Webb Telescope was this tight group of galaxies. This is Log Item 1025 in my observation log, when I imaged it with my 104mm refractor.

Keywords: NGC7317, Stephan’s Quintet, Galaxy, Pegasus